frosting tip

don't use vegetable oil to make frosting.  i baked a strawberry cake today from a mix.  the box had a pic of a slice of strawberry cake with white frosting and i thought, "mm, that looks mighty tasty!"  i find a recipe for white frosting and it says to use shortening.  ok, what EXACTLY does that mean?  i look it up in the dictionary and it says butter or vegetable oil.  because veggie oil mixes easier than butter, i use it.  i add vanilla extract, almond extract and tons of powdered sugar.  but when i'm mixing, it's not smooth at all.  so then i decide to microwave it for 30 seconds which melts the sugar but for some reason the vegetable oil keeps separating out!  so it looks like icing and a blob of oil sitting on top.  i use some icing on a couple slices of cake.  it tastes good, just like regular icing but i can't manage to get over the fact that the oil is sweating out of the sugar concoction.  eventually i decide to dump it.   next time i'll use butter to make frosting.